Leaders\u2019 competence and warmth: Their relationships with employees\u2019 well-being and organizational effectiveness

The aim of this work was to investigate competence and warmth \u2014 the two basic dimensions of social judgment \u2014 as dimensions employees use to evaluate their supervisors. A mediation model was tested in which supervisor\u2019s perceived competence and warmth were associated with relevant outcomes (lower burnout, weaker turnover intentions, more frequent citizenship behaviors) through the mediation of affective organizational commitment (AOC). In Study 1, data were collected from employees of a company in the water service sector. In Study 2, participants were financial promoters. In Study 3, the sample included employees from different organizations. As hypothesized, the perception of one\u2019s supervisor as competent (Studies 1-3) and warm (Study 3) was related to employees\u2019 lower burnout, weaker turnover intentions, more frequent prosocial behaviors through the mediation of AOC. Theoretical and practical implications of findings are discussed

Assessment of the worthwhileness of efficient driving in railway systems with high-receptivity power supplies

Eco-driving is one of the most important strategies for significantly reducing the energy consumption of railways with low investments. It consists of designing a way of driving a train to fulfil a target running time, consuming the minimum amount of energy. Most eco-driving energy savings come from the substitution of some braking periods with coasting periods. Nowadays, modern trains can use regenerative braking to recover the kinetic energy during deceleration phases. Therefore, if the receptivity of the railway system to regenerate energy is high, a question arises: is it worth designing eco-driving speed profiles? This paper assesses the energy benefits that eco-driving can provide in different scenarios to answer this question. Eco-driving is obtained by means of a multi-objective particle swarm optimization algorithm, combined with a detailed train simulator, to obtain realistic results. Eco-driving speed profiles are compared with a standard driving that performs the same running time. Real data from Spanish high-speed lines have been used to analyze the results in two case studies. Stretches fed by 1 × 25 kV and 2 × 25 kV AC power supply systems have been considered, as they present high receptivity to regenerate energy. Furthermore, the variations of the two most important factors that affect the regenerative energy usage have been studied: train motors efficiency ratio and catenary resistance. Results indicate that the greater the catenary resistance, the more advantageous eco-driving is. Similarly, the lower the motor efficiency, the greater the energy savings provided by efficient driving. Despite the differences observed in energy savings, the main conclusion is that eco-driving always provides significant energy savings, even in the case of the most receptive power supply network. Therefore, this paper has demonstrated that efforts in improving regenerated energy usage must not neglect the role of eco-driving in railway efficiency

Mapping the structural diversity of C60 carbon clusters and their infrared spectra

The current debate about the nature of the carbonaceous material carrying the infrared (IR) emission spectra of planetary and proto-planetary nebulae, including the broad plateaus, calls for further studies on the interplay between structure and spectroscopy of carbon-based compounds of astrophysical interest. The recent observation of C60 buckminsterfullerene in space suggests that carbon clusters of similar size may also be relevant. In the present work, broad statistical samples of C60 isomers were computationally determined without any bias using a reactive force field, their IR spectra being subsequently obtained following local optimization with the density-functional-based tight-binding theory. Structural analysis reveals four main structural families identified as cages, planar polycyclic aromatics, pretzels, and branched. Comparison with available astronomical spectra indicates that only the cage family could contribute to the plateau observed in the 6-9 micron region. The present framework shows great promise to explore and relate structural and spectroscopic features in more diverse and possibly hydrogenated carbonaceous compounds, in relation with astronomical observations

Surgical treatment of an aseptic fistulized acromioclavicular joint cyst: a case report and review of the literature.

An acromioclavicular joint cyst is an uncommonly reported condition, which seems to result from a massive rotator cuff tear and degenerative osteoarthritis of the acromioclavicular joint. We present the case of an 81-year-old man affected by an acromioclavicular joint cyst, associated to a massive rotator cuff tear, proximal migration of the humeral head and osteoarthritis of the gleno-humeral joint. The mass was 7 x 2.5 cm in size and the overlying skin presented a fistula that drained clear synovial-like fluid. Plain X-ray examination of the left shoulder showed proximal migration of the humeral head migration and osteoarthritis of the gleno-humeral joint, and further MRI evaluation confirmed the clinical diagnosis of a complete rotator cuff tear and observed a large subcutaneous cyst in communication with the degenerative acromioclavicular joint. The patient underwent surgical excision of the cyst and lateral resection of the clavicle to prevent disease recurrence. To the best of our knowledge, this is the first reported case of an acromioclavicular joint cyst complicated by an aseptic fistula resulting from multiple aspirations

Torsional response and stiffening of individual multi-walled carbon nanotubes

We report on the characterization of torsional oscillators which use multi-walled carbon nanotubes as the spring elements. Through atomic-force-microscope force-distance measurements we are able to apply torsional strains to the nanotubes and measure their torsional spring constants and effective shear moduli. We find that the effective shear moduli cover a broad range, with the largest values near the theoretically predicted value. The data also suggest that the nanotubes are stiffened by repeated flexing.Comment: 4 page

Atomic Scale Sliding and Rolling of Carbon Nanotubes

A carbon nanotube is an ideal object for understanding the atomic scale aspects of interface interaction and friction. Using molecular statics and dynamics methods different types of motion of nanotubes on a graphite surface are investigated. We found that each nanotube has unique equilibrium orientations with sharp potential energy minima. This leads to atomic scale locking of the nanotube. The effective contact area and the total interaction energy scale with the square root of the radius. Sliding and rolling of nanotubes have different characters. The potential energy barriers for sliding nanotubes are higher than that for perfect rolling. When the nanotube is pushed, we observe a combination of atomic scale spinning and sliding motion. The result is rolling with the friction force comparable to sliding.Comment: 4 pages (two column) 6 figures - one ep

Treatment of Severe Post-traumatic Bone Defects With Autologous Stem Cells Loaded on Allogeneic Scaffolds.

Mesenchymal stem cells may differentiate into angiogenic and osteoprogenitor cells. The effectiveness of autologous pluripotent mesenchymal cells for treating bone defects has not been investigated in humans. We present a case series to evaluate the rationale of using nucleated cells from autologous bone marrow aspirates in the treatment of severe bone defects that failed to respond to traditional treatments. Ten adult patients (mean age, 49.6-years-old) with severe bone defects were included in this study. Lower limb bone defects were >or=5 cm3 in size, and upper limb defects .or=2 cm3. Before surgery, patients were tested for antibodies to common pathogens. Treatment consisted of bone allogeneic scaffold enriched with bone marrow nucleated cells harvested from the iliac crest and concentrated using an FDA-approved device. Postsurgery clinical and radiographic follow-up was performed at 1, 3, 6, and 12 months. To assess viability, morphology, and immunophenotype, bone marrow nucleated cells were cultured in vitro, tested for sterility, and assayed for the possible replication of adventitious (contaminating) viruses. In 9 of 10 patients, both clinical and radiographic healing of the bone defect along with bone graft integration were observed (mean time, 5.6 months); one patient failed to respond. No post-operative complications were observed. Bone marrow nucleated cells were enriched 4.49-fold by a single concentration step, and these enriched cells were free of microbial contamination. The immunophenotype of adherent cells was compatible with that of mesenchymal stem cells. We detected the replication of Epstein-Barr virus in 2/10 bone marrow cell cultures tested. Hepatitis B virus, cytomegalovirus, parvovirus B19, and endogenous retrovirus HERV-K replication were not detected. Overall, 470 to 1,150 million nucleated cells were grafted into each patient. This case series, with a mean follow-up of almost 2 years, demonstrates that an allogeneic bone scaffold enriched with concentrated autologous bone marrow cells obtained from the iliac crest provides orthopedic surgeons a novel option for treating important bone defects that are unresponsive to traditional therapies

Deregulated expression of aurora kinases is not a prognostic biomarker in papillary thyroid cancer patients.

Abstract A number of reports indicated that Aurora-A or Aurora-B overexpression represented a negative prognostic factor in several human malignancies. In thyroid cancer tissues a deregulated expression of Aurora kinases has been also demonstrated, butno information regarding its possible prognostic role in differentiated thyroid cancer is available. Here, weevaluated Aurora-A and Aurora-B mRNA expression and its prognostic relevance in a series of 87 papillary thyroid cancers (PTC), with a median follow-up of 63 months. The analysis of Aurora-A and Aurora-B mRNA levels in PTC tissues, compared to normal matched tissues, revealed that their expression was either up-or down-regulatedin the majority of cancer tissues. In particular, Aurora-A and Aurora-B mRNA levels were altered, respectively, in 55 (63.2%) and 79 (90.8%) out of the 87 PTC analyzed. A significant positive correlation between Aurora-A and Aurora-B mRNAswas observed (p=0.001). The expression of both Aurora genes was not affected by the BRAF(V600E) mutation. Univariate, multivariate and Kaplan-Mayer analyses documented the lack of association between Aurora-A or Aurora-B expression and clinicopathological parameterssuch as gender, age, tumor size, histology, TNM stage, lymph node metastasis and BRAF status as well asdisease recurrences or disease-free interval. Only Aurora-B mRNA was significantly higher in T(3-4) tissues, with respect to T(1-2) PTC tissues. The data reported here demonstrate that the expression of Aurora kinases is deregulated in the majority of PTC tissues, likely contributing to PTC progression. However, differently from other human solid cancers, detection of Aurora-A or Aurora-B mRNAs is not a prognostic biomarker inPTC patients

Photoionization spectroscopy of CH3C3N in the vacuum-ultraviolet range

International audienceUsing vacuum-ultraviolet (VUV) synchrotron radiation, threshold and dissociative photoionization of cyanopropyne (CH3C3N) in the gas phase have been studied from 86 000 cm−1 up to 180 000 cm−1 by recording Threshold-PhotoElectron Spectrum (TPES) and PhotoIon Yield (PIY). Ionization energies of the four lowest electronic states X̃+2E,Ã+2A1,B̃+2E and C̃+ of CH3C3N+ are derived from the TPES with a better accuracy than previously reported. The adiabatic ionization potential of CH3C3N is measured as 86872±20 cm−1. A description of the vibrational structure of these states is proposed leading to the first determination of the vibrational frequencies for most modes. The vibrational assignments of the X̃+ state are supported by density functional theory calculations. In addition, dissociative photoionization spectra have been recorded for several cationic fragments in the range 12–15.5 eV (96 790–125 000 cm−1) and they bring new information on the photophysics of CH3C3N+. Threshold energies for the cationic dissociative channels leading to CH2C3N+, CHC3N+, HC3H+, HCNH+ and CH3+ have been measured for the first time and are compared with quantum chemical calculations

Conductance of Distorted Carbon Nanotubes

We have calculated the effects of structural distortions of armchair carbon nanotubes on their electrical transport properties. We found that the bending of the nanotubes decreases their transmission function in certain energy ranges and leads to an increased electrical resistance. Electronic structure calculations show that these energy ranges contain localized states with significant $\sigma$-$\pi$ hybridization resulting from the increased curvature produced by bending. Our calculations of the contact resistance show that the large contact resistances observed for SWNTs are likely due to the weak coupling of the NT to the metal in side bonded NT-metal configurations.Comment: 5 pages RevTeX including 4 figures, submitted to PR